Write programs,
Chat with friends,
Play games,
Surf the WWW,
Read/write e-mail,
Listen to the radio!,
Read software,
Use software,
Check spelling,
Write documents,
Access a more up to date dictionary,
Access a more up to date encyclopedia,
e.t.c.

web surfing - usually research for a given topic or posting in forums such as this
e-mail
text editing
typesetting (booklets (sometimes combined with the music listed below), brochures, etc.)
musical typesetting (lilypond)
programming
writing correspondence
systems administration
pushing the limits, boundaries, and frontiers of simplicity and efficiency in computing

My windows XP is used as a home computer 4 the family. I use it mostly to play chess, www and mail
My netbsd is used to everything else that is cool , writing code, hosting sites, compiling programs, NetBSD Apache PhP MySQL env, FW, I use to have it as IDS sometimes, etc.
I use to have a PVR in debian for some years ago, but i got mad with the quality of drivers and my wife had problems to switch the X server to the different outputs so it went windows XP with GBPVR (gbpvr.com).
I do work with computers all the day long 2, the main thing is security on unix and a lot of appliance boxes.
Reg /T

I've got an iMac at work that I use in the execution of my duties as a systems administrator using some of the following: iTerm, TextMate, DiskWarrior, Flash8, FileZilla, Firefox3, Gimp, Adium, VMWare Fusion, CapturMe, Chicken of the VNC, Data Rescue, Toast

I've got a workstation at home that's mostly just used for surfing and, when the need arises, working to resolve issues from home at 3 am. Some of the following get used: Firefox2, PuTTY, HyperTerm, Pidgin

I'm amazed at the number of people who actually admit they use their computers for porn.

As for me, I mainly use mine to check email, communicate with people on IRC, Jabber, and AIM, surf the Web, keeping my LAN going, learning system administration and programming (in that order; I'm definitely more of a sysadmin than a programmer), listening to certain audio streams from a certain Web site dedicated to a certain video game, all of which shall remain nameless, and yes - the occasional porn.